Postnatal development of the light response of the dopaminergic neurons in the rat retina.
The effect of light on retinal dopamine (DA) synthesis and content in dark-adapted rats was assessed 15 h and 2, 4, 7 and 16 days after eye opening (13 to 14 days after birth). The accumulation of dihydroxyphenylalanine (DOPA) following inhibition of its decarboxylation was used to estimate DA synthesis. At 7 and 16 days, but not earlier, light significantly augmented DOPA formation. These increases were as dramatic as those reported for adult rats. DA in dark-adapted retinas ranged from 0 (undetectable) at 15 h to 83% of adult levels at 16 days, but were only 36% of that of adult retinas at 7 days. Light produced a significant decline in DA at 16 days but not at any other time point. These results indicate that the dopaminergic neurons synthesize transmitter and respond to light at a time when the neuronal pools of DA are not yet mature.
D000375:Aging; D000818:Animals; D065105:Aromatic Amino Acid Decarboxylase Inhibitors; D003623:Dark Adaptation; D004295:Dihydroxyphenylalanine / Q000378:metabolism; D004298:Dopamine / Q000096:biosynthesis*; D006834:Hydrazines / Q000494:pharmacology; D008027:Light; D009474:Neurons / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D012160:Retina / Q000254:growth & development* / Q000378:metabolism / Q000528:radiation effects
D065105:Aromatic Amino Acid Decarboxylase Inhibitors; D006834:Hydrazines; D004295:Dihydroxyphenylalanine; C004297:3-hydroxybenzylhydrazine; D004298:Dopamine